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        <script type="text/javascript">
            // 箭头函数的 this 并非实例化对象的 this
            var person1 = {
                name: '日天',
                age: 22,
                fav:function(){
                    console.log(this)
                    console.log(this.name)
                }
            }
            //person1.fav();
            var person2 = {
                name: '日地',
                age: 21,
                fav:() => {
                    console.log(this)
                    console.log(this.person1)
                }
            }
            //person2.fav()

            // 箭头函数    arguments
            var person3 = {
                name: '日天',
                age: 22,
                fav: function(){
                    console.log(arguments)
                }
            }
            person3.fav()

            var person4 = {
                name: '日地',
                age: 21,
                fav: () => {
                    // 不能使用
                    console.log(arguments)
                }
            }
            person4.fav()
        </script>
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